The molecular basis of the actions of three groups of proteins that are involved in aspects of complex carbohydrate function will be examined. 1) GLYCOSYLTRRANSFERASES that catalyze the synthesis of oligosaccharides in glycoconjugates will be examined in several ways. A) Selected transferases will be isolated and their properties characterized. B) Antibodies to selected transferases will be used to localize the enzymes intracellularly, to examine whether they exist as multienzyme complexes and as probes for the structure of the transferase. C) The biosynthetic roles of selected transferases will be sought. D) The possible role of covalently bound lipids in the transferases and the effect of biological lipids on the properties of selected transferases will be examined. E) Genes for selected transferases will be cloned to obtain sufficient enzyme for structure/function studies. 2) LECTINS. Vertebrate liver lectins, primarily the fucose-specific lectin will be examined from several aspects. A) Antibodies against the lectins will be used to define the subcellular localization of lectins. B) Naturally occurring ligands for the lectins will be sought. C) Structural studies on the fucose lectin will be performed. D) The possible roles of lectins during embryonic and fetal development will be sought. 3) ENZYMES FOR NUCLEOTIDESUGAR INTERCONVERSION. Key enzymes that act in nucleotide sugar biosynthesis will be isolated and characterized with emphasis on understanding the molecular mechanisms that act in regulation of nucleotidesugar biosynthesis.